Method of milling flour.



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mmoo 0F mums FLOUR. APPLICATION LED ML 8. l9-

Patented Dec. 17, 1918.

2 SHEETS-SHEET I.

ROWAN T. F. DQDIDS,- F DECATUR, ILLINOIS.

METHOD or MILLING FLOUR.-

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Specification of Letters Patent.

Patented Dec. 17, 1918.

Application filed March 8, 1917. Serial No, 153,380.

To all whom-it may concern:

Be it known that I, ROWAN T. F. Donns,

a citizen of the United States, residing at Decatur, in the county of Macon and State of Illinois, have invented a new and useful Improvement in Methods of Milling Flour, of which the following is a full, clear, and

exact description, reference being had to the accompanying drawings, forming part of this specification, in Which- Figure 1 is a longitudinal sectional view on the line I-I of Fig. 2, showing one form of apparatus for carrying out my invention,

and

Fig. 2 is a transverse sectional View on the line II-II of Fig. 1.

My invention has relation to an improved method of milling flour; and is designed to provide a method of milling which will not only largely increase the quantity of flour which can be produced in a predetermined time from a m1ll of an given capacity, but which will also materia ly improve the quality of. the flour produced.

I have discovered that by increasing the speed of the milling rolls considerably above the speeds which are generally in use at the present time, I am able to secure very important results.

In accordance with my invention, the milling rolls are driven at such a high velocity ,as to produce rotating air currents of high velocity between the rolls. These high velocity air currents have several important eifects. One of these is that as these air currents meet at the point of contact of the rolls they exert a very consider able disintegrating act-ion upon'the grain and flour independently of the crushing action of the rolls. Furthermore, the air currents exert an aerating action upon the flour which is extremely beneficial in'improving the quality of the flour and making it of a more uniform and even grade.

Flour produced by my invention makes a superior bread, the yeast acting more uniforml'y thereon. ,The air currents also have a bleaching action upon the flour. They also prevent heating of the rolls and largely reduce the grinding friction thereof. After running a mill an entire day in accordance with my invention, the rolls are found to be nearly as cool as when the mill was started.

The precise nature of my invention will be best understood by reference to the accompanying drawings, which will now be described, it being premised, however, that changes may be made in the construction of the mill and arrangement of the parts, without departing from the spirit and scope of my; invention, as defined in the appended claims.

.In the drawings the reference characters A and B designate complete units, each of which comprises two sets of grinding rolls "or elements, a bolting reel for each set of grinding elements, and conveyers for conveying the material from the grinding elements to their respective bolting reels. Each of the units comprises a roll compartment C, a gearing compartment D, and a reel compartment which is divided into two sections E and E by a partitionv E In the drawings I have shown a mill built up of two duplicate units, and which comprises four pairs of grinding elements, but I desire to be understood that my method is applicable to a single set of grinding elements and a bolting reel, as well as to a larger number of grinding elements and bolting reels.

As this application forms a continuation in partof my co-pending applications Serial Nos. 22,570 and 70,175, issued March 13, 1917, Nos. 1,218,634 and 1,218,933, respectively, 1 will merely describe the mill in a general way and not in detail.

Inthe mill shown in the drawings, the first set of grinding elements or rolls 2 and 2 which are located in the compartment C of unit A are connected by means of a conveyer 2 with a reel 2 in compartments E and E. of rolls in the compartment C which are connected to their respective reels by means of conveyers 3 41 and 5*. I

The various rolls. may be driven in any suitable manner, as by means of belts connected to the pulley 6 on the front of the machine and in the compartment D, in the manner more fully shown and described in my Patent No. 1,218,933. The driving means should be such that one of the rolls of each set is driven at a higher ratei of speed than the other roll of the set, and

that both shall be driven at an abnormal rate of speed. By the term abnormal as used herein and in the appended claims with reference to the speed of the rolls, I have reference to a speedwhich is very materially greater than that at present used and which is preferably in no case less than 600'revolu- 3, 3; 4, e'lf; 5', 5 are similar sets tious per minute. for the roll of each set having the higher speed. As the speed 18 increased above 600 revolutions per minute,

the effect upon the flour produced becomes very noticeable and I prefer to use speeds as high as 900 or 1000 revolutions per minute with the higher speed rolls, the lower speed rolls of each set being also driven at a much higher speed than is customary. For the breaking rolls the difi'erence in the speed of the two rolls of the set is preferably greater than in the case of the reducing rolls. For instance, the higher speed roll of the breaking set may be driven at a speed three times that of the lower speed roll, while for the reducing rolls, speeds of two to one give good results.

While my invention is not limited to the use of rolls of any given size, in general practice I prefer to use rolls of approximately 5 inches in diameter, as I have discovered that better results can be obtained by using relatively small rolls driven at a high speed in order to shorten the arc of contact between the two rolls of a set.

The compartment E is provided with slant boards below the reels for directing the flour which passes through the fine mesh of these bolting reels to a flour hopper 9 below the reels, the flour being fed to a suitable point by means of a conveyer 10.

In the compartment E I provide slant boards 11 for conveying the material which passes through the coarse mesh cloth of the reel 2 to a hopper and 13 is a conveyer for conveying this coarse material to a suitable elevator 1 L which is connected to a feed spout 15.

The reels may be constructed in the manner described and illustrated in my Patent No. 1,218,933, and in which the reels a're arranged to draw the fine woody particles in the ground material toward the center and convey it outwardly toward the central outlets.

Located within the compartment C is a fan casing 19 having an open tube 20 which communicates with the interior of the casing, and through which the dust from the compartment is drawn off, the upper portion of the compartment being provided with canvas covered openings or windows 21 for ,the admission of air. Similar openings are provided in the compartment E, and 23 is a pipe leading from said compartment to a suitable exhausting device. The compartment E is also provided with openings for the admission of air, as well as an off-take pipe 25 for exhausting the dust from the compartment. This pipe 25 may be arranged, as shown, so as to be common to and to exhaust the air from both the compartments of reels. The off-take pipes 24 and 25 may be connected to any suitable exhausting device.

Located within the con'ipartment C are the feeding devices 26 and 27, which are arranged to be agitated by means of a cam 28. The feed device 26 is arranged above the upper sets of rolls, while the feed device 27 is arranged above the lower sets of rolls.

The operation is as follows: The grain to be ground is fed through a chute 29 to the right hand side of the feed device 20, and is fed to the rolls 2 and 2, the ground material from said rolls is fed by means of-conveyer 2" to the reel 2. The flour which passes through the fine mesh at the right hand side of the reel 2 falls directly upon one of the slant boards and from there to the slant boards 9. The coarse material which passes through the reel 2 falls upon the slant boards 11 and thence to the slant boards of the hopper .of the conveyer 13. The material which does not pass through the coarse cloth of the reel .2 is picked up by means of the usual buckets 30 and fed into the conveyer 2 and is fed to a conveyer 31 by means of which it is fed to the right hand side of the feed device 27, and from which it is fed to the rolls 3 and 3. The ground material from rolls 3 and 3 is fed by means of con veyer 3 to its reel. The flour from said reel passes directly to the slant boards 9, while the coarse material which passes through the coarse mesh of the cloth of said reel is fed to the conveyer 13. The material is fed by conveyer 13 to the elevator 14, and from which it is fed by means of the connection 15 to the left hand side of the feed device 26, and is fed thereby to the rolls 4: and 4.

The ground material from the rolls 4 and 4 is fed by means of conveyer 4 toits reel, and the flour which passes through the fine mesh of this reel passes directly to; the slant boards. The coarse material which passes through the coarse mesh in the compartment E and isconveyed by means of conveyer to the left hand side of the feed device 27, and from which it is fed to the rolls 5 and 5. The ground material from the rolls 5 and 5 is fed by means of conveyer 5" to the reel 5, which is provided with fine mesh cloth in the compartment E, and the flour which falls through said cloth passes to the conveyer 10 over the slant boards 9, while the refuse is taken off through the conveyer 5".

I claim:

1. The method of milling flour which con sists in feeding grain to grinding rolls and rotating the grinding rolls at an abnormally high rate of speed to cause a current of air to pass between the rolls, one of said rolls being driven at a speed in excess of 000 revolutions per minute.

2. The method of milling flour which consists in feeding grain to grinding rolls and rotating the grinding rolls at a speed in excess of 600 revolutions per minute to cause a current of air to pass between the rolls, then passing the material through a bolting reel to remove the fine particles, and passing the coarser material through a second set of grinding rolls which are rotated at a speed in excess of 600 revolutions per minute to cause a current of air to pass between the rolls to aerate and disintegrate the material.

The method of milling flour, which consists in feeding grain to grinding rolls and rotating the rolls at an abnormally high rate of speed, and rotating one of the rolls at a higher rate of speed than the other and at a speed in excess of 600 revolutions per minute to aerate and disintegrate the material being ground.

4. -The method of milling flour which cou sists in feeding grain to grinding rolls and rotating the grinding rolls at an abnormally high rate of speed to cause the current of air to ass between the rolls, one of said rolls being driven at a speed in excess of 600 revolutions per minute, and subjecting the material to a current of air to draw 0E the fine particles.

5. The method of milling flour, which consists in passing the'material to be ground between rolls some of which are driven at a speed of at least 900 revolutions per minute, to rotate and disintegrate the material being ground, and subjecting the material to the action of a current of air to draw off the fine particles.

In testimony whereof, I have hereunto set my hand.

' ROWAN T. F. DODDS.

Witnesses I E. W. SoHoLL, CALEB S. SCHULTZ. 

